Novel perchlorinated disilenes and germasilenes and also neopentatetrelanes, a method for the preparation thereof and use thereof

ABSTRACT

The invention provides disilenes, germasilenes and neopentatetrelanes, a method for the preparation thereof and use thereof.

The present invention relates to disilenes, germasilenes and neopentatetrelanes, a method for the preparation thereof and use thereof.

Practically nothing is currently known about germasilenes and neopentatetrelanes. Thus, for the purposes of fundamental research, the aim is to find novel compounds and to seek novel preparation routes, in particular also with respect to potential industrial and optionally improvable applications.

The patent application EP 3 410 466 A1 discloses trichlorosilyltrichlorogermane and chlorosilylarylgermanes, which are obtained in dissolved form and by reacting an arylchlorogermane with hexachlorodisilane in the presence of a catalyst.

EP 3 409 645 A1 discloses and prepares triphenylgermylsilane by dissolving trichlorosilyltriphenylgermane and AlCl₃ in a solvent and is reduced by addition of a hydride.

EP 3 409 678 A1 presents various halogermanides which are obtained by reacting GeCl₄ with hexachlorodisilane.

The object of the present invention is to provide novel silicon-germanium compounds and a method for the preparation thereof.

The object was solved by reacting tris(trichlorosilyl)tetrelides with aluminium trichloride in the presence of electrophilic substances. These compounds represent a novel substance class.

The invention provides the comp und neopentatetrelane of the general formula C

wherein each independently in pairs E is Si or Ge, E′ is C, Si or Ge, and R is Cl, Me, Et or Ph.

For the preparation, a synthetic route starting from inexpensive reactants has been found.

The invention therefore also provides a method for preparing the neopentatetrelane C according to the invention, in which

-   -   (a) a salt [X₄N]- or [X₄P]-tris(trichlorosilyl)tetrelide, where         the radical X is selected from Me, Et, iPr, nBu or Ph,

the tris(trichlorosilyl)tetrelide having the general formula A⁻

where E=Si or Ge,

is dissolved in a solvent, and subsequently either the steps b and c, or the step d is carried out

-   -   (b) the tris(trichlorosilyl)tetrelide dissolved in step a is         reacted in the presence of a Lewis acid, wherein a disilene or         germasilene is obtained having the general formula B

where E=Si or Ge, and

-   -   (c) the disilene or germasilene B is reacted with a tetrel         chloride R₃E′-Cl at a temperature of −80° C. to 40° C., where         E′=C, Si or Ge, and where R=Cl, Me, Et or Ph, wherein the         neopentatetrelane C is obtained, or     -   (d) the tris(trichlorosilyl)tetrelide dissolved in step a is         introduced

into a suspension at a temperature of −80° C. to 40° C. comprising a Lewis acid, a tetrel chloride R₃E′-Cl where E′=C, Si or Ge, and where R=Cl, Me, Et or Ph,

and a solvent, wherein the neopentatetrelane C is obtained.

The method according to the invention has the advantage that the composition of the neopentatetrelanes obtained can be varied over a wide range by a simple change of electrophilic substrate. As a result, a multiplicity of derivatives having customized properties can be prepared for the production of semiconductor materials. In particular, the Si/Ge ratio can be set in a defined manner in the method according to the invention and therefore produces neopentatetrelanes C having an outstanding importance for the production of semiconductor materials.

The invention therefore also relates to the use of the neopentatetrelane C according to the invention or obtained according to the invention for generating GeSi layers.

The invention is explained in more detail below.

It may be advantageous in the method according to the invention to set the temperature during the conversion reaction within the range from −100° C. to 40° C.

In step d of the method according to the invention, in the case that E=Si is selected, the conversion reaction already takes place at a temperature of −78° C.

The compound of the structure B, in the case that E=Ge, is also referred to as a “germasilene” in the context of the invention.

The preparation of a suspension comprising the components listed in step d is known to those skilled in the art.

The solution obtained according to step a is preferably added dropwise to the suspension, if step d is carried out.

The method according to the invention according to steps a, b and c has the advantage that the di- or germasilene B can be stored by reacting the tris(trichlorosilyl)tetrelide dissolved in step a in the presence of a Lewis acid together with at least one further reagent in step b and the method discontinued after step b.

The additional reagent used is preferably anthracene or an anthracene derivative, preferably 2,7-di-tert-butylanthracene.

The invention therefore also provides compounds of the general formula B, prepared by the method according to the invention, wherein anthracene or an anthracene derivative is additionally used in step b of the method and the method is discontinued after step b prior to step c.

Preferably, B may be obtained in a melt-sealed NMR tube, in which E=Ge is selected and (A⁻), AlCl₃ and anthracene are weighed in in equimolar amounts, C₆D_(G) is added and the NMR tube is subsequently melt-sealed under vacuum and immediately heated to 120° C.

In the method according to the invention, the steps b and c, or the step d, are preferably carried out at room temperature. In the context of the invention “ambient temperature” is understood to mean the temperature 20° C.

In the method according to the invention, the solvent preferably used in step a and/or in step d may preferably be dichloromethane, benzene, C₆D₆, or CD₂Cl₂. With the solvent dichloromethane or CD₂Cl₂ used by way of preference, the neopentatetrelane C according to the invention may be obtained. In the case of the preparation according to the invention of (Cl₃Si)₃GeSiMe₃, preference may also be given to using C₆D₆.

In the method according to the invention, preference may also be given to using X=nBu in step a.

It may be advantageous in step b or d of the method according to the invention to use AlCl₃ as Lewis acid.

In the method according to the invention, the step d or the steps b and c may preferably be carried out with mixing, preferably with stirring, and over a total period of 1 to 24 hours, preferably in total 12 h, and preferably under protective gas, preferably under nitrogen or argon,

and subsequently

the solvent is removed, preferably in a dry oxygen-free environment, particularly preferably in an isolated environment,

further preferably at standard pressure or a pressure in the range of 1 to 500 hPa, particularly preferably at standard pressure,

and the neopentatetrelane C formed is extracted, preferably with n-hexane, particularly preferably with boiling n-hexane.

The examples which follow provide additional illustration of the present invention without restricting the subject-matter. In the context of the invention, “ambient conditions” are understood to mean the parameters of the standard atmosphere at 20° C. and a pressure of 1013.25 hPa, the so-called “ambient pressure”.

Analytical Methods for Determination of the Crystal Structure

The data for all crystal structures were collected at 173 K using a STOE IPDS II two-circle difiractometer with a Genix microfocus tube having mirror optics using MoK, radiation (A=0.71073 Å) and scaled using the frame scaling procedure of the X-AREA program (Stoe & Cie, 2002). The structures were solved by direct methods with the aid of the SHELXS program (Sheldrick, 2008) and refined on F² by the full matrix least squares technique. Cell parameters were determined by refinement on θ values of the reflections with I>6σ(I).

EXAMPLE 1: PREPARATION OF NEOPENTATETRELANE (C) WHERE E-SI, R-CL AND E′-GE

A solution of 0.361 g or 0.535 mmol corresponding to 1.0 eq of [nBu.N][(Cl₃Si)₃Si] in 6 ml of CH₂Cl₂ solvent was added dropwise to a suspension of 0.073 g or 0.547 mmol corresponding to 1.0 eq of AlCl₃ and 0.144 g or 0.671 mmol corresponding to 1.3 eq of GeCl₄ in 5 ml of CH₂Cl₂ solvent, until all the solid had dissolved. An orange-coloured solution was obtained which was stirred for 12 hours under ambient conditions.

The solvent was removed at atmospheric pressure and the orange-coloured solid was removed with 3×10 ml of n-hexane. This gave 0.193 g or 0.316 mmol, corresponding to a proportion of 59% neopentatetrelane (C) as a colourless liquid.

The ²⁹Si-NMR spectrum of this example is shown in FIG. 1.

Results of a ¹H, ¹³C and ²⁹Si NMR spectroscopic analysis:

²⁹Si NMR (99.4 MHz, CD₂Cl₂):

δ=−0.25 ((Cl₃Si)₃SiGeCl₃), −32.1 ppm ((Cl₃Si)₃SiGeCl₃)

Hydrogenation of this Neopentatetrelane.

In a melt-sealable NMR tube, 0.55 ml of a 1M solution of (iBu₂)AlH in C₆H₁₂, which corresponds to 0.08 g or 0.55 mmol and thus 14.0 eq of (iBu₂)AlH, and 0.25 ml Et₂O were added to 0.02 g or 0.04 mmol corresponding to 1.0 eq of neopentatetrelane.

After 42 hours, the colourless solution was investigated by NMR spectroscopy. Results:

¹H NMR (500.2 MHz, C₆H₁₂): δ=3.36 ppm (q, ⁴J_(HH)=7.0 Hz, (H₃Si)₃SiGeH₃);

²⁹Si NMR (99.4 MHz, C₆H₁₂): δ=−95.4 ppm (q, ¹J_(Si-F)=200 Hz, (H₃Si)₃SiGeH₃);

¹H/²⁹Si HSQC-NMR (500.2/99.4 MHz, C₆H₁₂): δ=3.36/−95.4 ppm;

¹H/²⁹Si HMBC-NMR (500.2/99.4 MHz, C₆H₁₂): δ=3.36/−95.4, 3.36/−136.9 ppm.

EXAMPLE 2: PREPARATION OF NEOPENTATETRELANE (C) WHERE E-E′=SI, UND R-ME

A solution of 0.238 g or 0.353 mmol corresponding to 1.0 eq of [nBu₄N][(Cl₃Si)Si] in 3 ml of CH₂Cl₂ solvent was added dropwise to a suspension of 0.049 g or 0.367 mmol corresponding to 1.0 eq of AlCl₃ and 0.073 g or 0.672 mmol corresponding to 1.9 eq of Me₃SiCl in 1 ml of CH₂Cl₂ solvent, until all the solid had dissolved. A colourless solution was obtained.

The solvent was removed with stirring at atmospheric pressure and the colourless solid was extracted with 3×3 ml of n-hexane. This gave 0.134 g or 0.266 mmol, corresponding to a proportion of 75% neopentatetrelane (C) as a colourless crystalline solid.

The ²⁹Si-NMR spectrum of this example is shown in FIG. 2.

Results of a ¹H, ¹³C and ²⁹Si NMR spectroscopic analysis:

²⁹Si NMR (99.4 MHz, CD₂Cl₂): δ=10.5 ppm (s, (Cl₃)₃SiSiMe₃), −3.5 ppm (sext., ²J_(H,Si)=7.0 Hz, (Cl₃Si)₃SiSiMe₃), −83.5 ppm (m, (Cl₃Si)SiSiMe₃).

¹H NMR (500.2 MHz, CD₂Cl₂): δ=0.58 ppm;

¹³C{¹H} NMR (125.8 MHz, CD₂Cl₂): δ=0.4 ppm;

¹H/¹³C HSQC NMR (500.2/125.8 MHz, CD₂Cl₂): δ=0.58/0.4 ppm;

¹H/²⁹Si HMBC NMR (500.2/99.4 MHz, CD₂Cl₂): δ=0.58/−3.5, 0.58/−83.5 ppm.

EXAMPLE 3: PREPARATION OF NEOPENTATETRELANE (C), WHERE E-GE, E′-SI, AND R=ME

In a melt-sealed NMR tube, 0.100 g or 0.139 mmol corresponding to 1.0 eq of [nBu₄N][(Cl₃Si)₃Ge],

0.019 g or 0.142 mmol corresponding to 1.0 eq of AlCl₃ and

0.093 g or 0.856 mmol corresponding to 6.2 eq of Me₃SiCl

were reacted in 0.8 ml of CD₂Cl₂ solvent, whereby a yellow solution with orange coloured solid was obtained.

The solvent was removed at atmospheric pressure and the solid was isolated with 3×3 ml of boiling n-hexane. This gave 0.073 g or 0.133 mmol, corresponding to a proportion of 96% neopentatetrelane (C) where E=Ge, E′=Si, and R=Me.

The ²⁹Si-NMR spectrum of this example is shown in FIG. 3.

Results of a ¹H, ¹³C and ²⁹Si NMR spectroscopic analysis:

²⁹Si NMR (99.4 MHz, CD₂Cl₂): δ=9.9 ppm (s, (Cl₃Si)₃GeSiMe₃),

7.2 ppm (sext., ²J_(H,Si)=7.0 Hz, (Cl₃Si)₃GeSiMe₃).

¹H NMR (500.2 MHz, CD₂Cl₂): δ=0.61 ppm;

¹³C{¹H} NMR (125.8 MHz, CD₂Cl₂): δ=1.2 ppm;

¹H/¹³C HSQC NMR (500.2/125.8 MHz, CD₂Cl₂): δ=0.61/1.2 ppm;

¹H/²⁹Si HMBC NMR (500.2/99.4 MHz, CD₂Cl₂): δ=0.61/7.0 ppm.

EXAMPLE 4: PREPARATION OF NEOPENTATETRELANE (C), WHERE E-GE, E′-SI, AND R-ET

In a melt-sealed NMR tube, 0.10 g or 0.14 mmol corresponding to 1.0 eq of [nBu₄N][(Cl₃Si)₃Ge],

0.02 g or 0.14 mmol corresponding to 1.0 eq of AlCl₃ and

0.13 ml or 0.12 g corresponding to 5.6 eq of Et₃SiCl

were reacted in 0.8 ml of CD₂Cl₂ solvent, whereby a yellow solution was obtained.

The solvent was removed at atmospheric pressure.

By means of subsequent extraction with 3×3 ml of boiling n-hexane, removal of the solvent and Et₃SiCl, this gave 0.08 g or 0.14 mmol corresponding to a proportion of 97% neopentatetrelane (C) where E=Ge, E′=Si, and R=Et as a pale yellow solid.

The ²⁹Si-NMR spectrum of this example is shown in FIG. 4.

Results of a ¹H, ¹³C and ²⁹Si NMR spectroscopic analysis:

²⁹Si NMR (99.4 MHz, CD₂Cl₂): δ=21.4 ppm (m, (Cl₃Si)₃GeSiCH₂CH₃), 10.7 ppm (s,

(Cl₃Si)₃GeSiCH₂CH₃).

¹H NMR (500.2 MHz, CD₂Cl₂): δ=1.14 ppm (m, (Cl₃Si)₃GeSiCH₂CH₃);

¹³C{¹H} NMR (125.8 MHz, CD₂Cl₂): δ=8.4 ((Ca₃Si)₃GeSiCH₂CH₃), 6.5 ppm ((Cl₃Si)₃GeSiCH₂CH₃);

¹H/¹³C HMBC NMR (500.2/125.8 MHz, CD₂Cl₂): δ=1.14/8.4, 1.14/6.5 ppm;

¹H/²⁹Si HMBC NMR (500.2/99.4 MHz, CD₂Cl₂): δ=1.14/21.4 ppm.

EXAMPLE 5: PREPARATION OF NEOPENTATETRELANE (C), WHERE E=GE, E′-C, AND R=PH

In a melt-sealed NMR tube, 0.080 g or 0.111 mmol corresponding to 1.0 eq of [nBu₄N][(Cl₃Si)₃Ge],

0.015 g or 0.112 mmol corresponding to 1.0 eq of AlCl₃ and

0.031 g or 0.111 mmol corresponding to 1.0 eq of Ph₃CCl

were reacted in 0.7 ml of CD₂Cl₂ solvent, whereby a yellow solution with yellow solid was obtained.

The solvent was removed at atmospheric pressure.

By means of extraction with 3×3 ml of boiling n-hexane and subsequent crystallization, neopentatetrelane (C) where E=Ge, E′=C, and R=Ph was obtained in the form of yellow crystals.

The ²⁹Si {¹H}-NMR spectrum of this example is shown in FIG. 5A. FIG. 5B shows the crystal structure of this neopentatetrelane.

Results of a ¹H, ¹³C and ° Si NMR spectroscopic analysis:

²⁹Si NMR (99.4 MHz, CD₂Cl₂): δ=8.2 ppm.

¹H NMR (500.2 MHz, CD₂Cl₂): δ=7.38-7.28 ppm (m, (Cl₃Si)₃GeCPh₃),

δ=7.16-7.12 ppm (m, 2H, (Cl₃Si)₃GeCPh₃);

¹³C{¹H} NMR (125.8 MHz, CD₂Cl₂): δ=144.3 ((Cl₃Si)₃GeCPh₃(-ipso)),

131.4 ((Cl₃Si)₃GeCPh₃(-ortho)), 129.8 ((Cl₃Si)₃GeCPh₃(-para)),

128.2 ((Cl₃Si)₃GeCPh₃(-metha)), 70.3 ppm ((Cl₃Si)₃GeCPh₃);

¹H/¹³C HMBC NMR (500.2/125.8 MHz, CD₂Cl₂):

δ=7.38-7.28/144.3, 7.38-7.28/131.4, 7.38-7.28/129.8, 7.38-7.28/128.2, 7.16-7.12/7.16-7.12/144.3, 7.16-7.12/131.4, 7.16-7.12/129.8, 7.16-7.12/128.2, 7.16-7.12/70.3 ppm;

¹H/²⁹Si HMBC NMR (500.2/99.4 MHz, CD₂Cl₂): δ=7.16-7.12/8.2 ppm.

EXAMPLE 6: PREPARATION OF NEOPENTATETRELANE (C), WHERE E-GE, E′-SI, AND R=PH

In a melt-sealed NMR tube, 0.100 g or 0.139 mmol corresponding to 1.0 eq of [nBu₄N][(Cl₃Si)₃Ge],

0.019 g or 0.142 mmol corresponding to 1.0 eq of AlCl₃ and

0.041 g or 0.139 mmol corresponding to 1.0 eq of Ph₃SiCl

were reacted in 0.8 ml of CD₂Cl₂ solvent, whereby a yellow solution with yellow solid was obtained.

The solvent was removed at atmospheric pressure.

By means of extraction with 3×3 ml of boiling n-hexane and subsequent crystallization, neopentatetrelane (C) where E=Ge, E′=Si, and R=Ph was isolated in the form of yellow crystals.

The ²⁹Si-NMR spectrum of this example is shown in FIG. 6A. FIG. 6B shows the crystal structure of this neopentatetrelane.

Results of a ¹³C and ²⁹Si-NMR spectroscopic analysis:

²⁹Si NMR (99.4 MHz, CD₂Cl₂): δ=9.7 ppm (s, (Cl₃Si)₃GeSiPh₃),

−6.5 ppm (m, (Cl₃Si)₃GeSiPh₃).

¹³C{¹H} NMR (125.8 MHz, CD₂Cl₂): δ=137.1, 134.5, 131.7, 129.2 ppm.

EXAMPLE 7: PREPARATION OF NEOPENTATETRELANE (C), WHERE E-E′=GE AND R=PH

In a melt-sealed NMR tube, 0.081 g or 0.113 mmol corresponding to 1.0 eq of [nBu₄N][(ClSi)₃Ge],

0.015 g or 0.112 mmol corresponding to 1.0 eq of AlCl₃ and

0.038 g or 0.112 mmol corresponding to 1.0 eq of Ph₃GeCl

were reacted in 0.7 ml of CD₂Cl₂ solvent, whereby a pale yellow solution was obtained.

The solvent was removed at atmospheric pressure.

By means of extraction with 3×4 ml of n-hexane and subsequent crystallization, neopentatetrelane (C) where E=E′=Ge and R=Ph was isolated in the form of pale yellow crystals.

The ²⁹Si-NMR spectrum of this example is shown in FIG. 7A. FIG. 7B shows the crystal structure of this neopentatetrelane.

Results of a ¹H, ¹³C and ²⁹Si NMR spectroscopic analysis:

²⁹Si NMR (99.4 MHz, CD₂Cl₂): δ=9.2 ppm (s, (Cl₃Si)₃GeGePh₃).

¹H NMR (500.2 MHz, CD₂Cl₂): δ=7.65-7.64 ppm (m, 2H),

7.54-7.50 ppm (m, 1H), 7.49-7.46 ppm (m, 2H);

¹³C{¹H} NMR (125.8 MHz, CD₂Cl₂): δ=136.0, 133.1, 130.9, 129.4 ppm. 

1. A neopentatetrelane of the general formula C

wherein each independently in pairs E is Si or Ge; E′ is C, Si, or Ge; and R is Cl, Me, Et, or Ph.
 2. A method for preparing the neopentatetrelane C of claim 1, comprising: (a) dissolving a salt [X₄N]- or [X₄P]-tris(trichlorosilyl)tetrelide in a solvent, wherein the radical X is at least one selected from the group consisting of Me, Et, iPr, nBu, and Ph, wherein the tris(trichlorosilyl)tetrelide has the general formula A⁻

where wherein E=Si or Ge; (b) reacting the tris(trichlorosilyl)tetrelide dissolved in step (a) with a Lewis acid to produce a disilene or germasilene having the general formula B

wherein E=Si or Ge; and (c) reacting the disilene or germasilene B with a tetrel chloride R₃E′-Cl at a temperature of −80° C. to 40° C. to obtain the neopentatetrelane C, wherein E′=C, Si, or Ge, and R=Cl, Me, Et, or Ph; or (d) contacting the tris(trichlorosilyl)tetrelide dissolved in step (a) with a suspension at a temperature of −80° C. to 40° C. comprising a Lewis acid, a tetrel chloride R₃E′-Cl, and a solvent to obtain the neopentatetrelane C, wherein E′=C, Si, or Ge, and R=Cl, Me, Et, or Ph.
 3. The method of claim 2, wherein the steps (b) and (c), or the step (d), are or is carried out at room temperature.
 4. The method of claim 2, wherein the solvent used in step (a) and/or in step (d) is at least one independently selected from the group consisting of dichloromethane, benzene, C₆D₆, And CD₂Cl₂.
 5. The method of claim 2, wherein X=nBu.
 6. The method of claim 2, wherein the Lewis acid in step (b) or (d) is AlCl₃.
 7. The method of claim 2, wherein the step (d) the steps (b) and (c) are each carried out with mixing, the method further comprising after step (d) or (c) removing the solvent over a total period of 1 to 24 hours to extract the neopentatetrelane C.
 8. A compound of the general formula B,

wherein E=Si or Ge, prepared by a method comprising: (a) dissolving a salt [X₄N]- or [X₄P]-tris(trichlorosilyl)tetrelide in a solvent, wherein the radical X is at least one selected from the group consisting of Me, Et, iPr, nBu, and Ph, wherein the tris(trichlorosilyl)tetrelide has the general formula A⁻

wherein E=Si or Ge, (b) reacting the tris(trichlorosilyl)tetrelide dissolved in step (a) with a Lewis acid and an anthracene or an anthracene derivative to obtain the compound of the general formula B.
 9. A GeSi layer, comprising the neopentatetrelane C of claim
 1. 